EFFECTIVENESS OF ULTRASONIC IRRIGATION ON CALCIUM HYDROXIDE REMOVAL WITH DIFFERENT SOLUTIONS: AN IN VITRO STUDY

Background: Calcium hydroxide has been widely used in endodontics as an intracanal medicament. Before obturation, calcium hydroxide, an intracanal medicament should be completely removed from the root canal system sinceresidual calcium hydroxide might adversely affect the outcome of endodontic treatment results. Various irrigation techniques to remove this intracanal medicament have developed. The aim of this in vitro study was to evaluate the effectiveness in removing calcium hydroxide from the root canal, with or without using ultrasonic activation. Materials and methods: Sixty extracted single-rooted mandibular premolar were instrumented using ProTaper rotary instruments, filled with calcium hydroxide and divided into six groups (n=10/group). Subsequently, calcium hydroxide was removed by six different protocols. Group I, II, II were flushed using 2.5% NaOCl, 17% EDTA, 10% citric acid, respectively. Group IV, V, VI were flushed using the same irrigants respectively with ultrasonic activation. Finally, the roots were grooved longitudinally and split in two halves. Selected half of each tooth was observed under a stereomicroscope at 30x magnification to assess the residual calcium hydroxide score. Results: NaOCl 2,5% demonstrated the significantly higher score of residual calcium hydroxide than EDTA 17% and citric acid 10% (p<0.05). Groups combined with ultrasonic irrigation was significant lower than the others (p<0.05). Conclusion: None of the six techniques could remove all calcium hydroxide completely. Ultrasonic irrigation was more effective in removing calcium hydroxide than syringe delivery. Key words: calcium hydroxide, irrigation solution, ultrasonic irrigation